The former Girls Aloud singer, 33, told the show: "I was just a general worrier, it's in my nature, I would worry about the world.

"I was quite a depressed teenager. I didn't enjoy my teenage years at all."

She appeared on the programme with Childline founder Esther Rantzen, as the charity celebrates its 30th anniversary.

Sharing how she grew up feeling under too much "pressure" both at school and at home to do well in exams, Cheryl said: "I would not go back to my teenage years for love nor money."

The charity hopes that her high television profile will be more accessible to young people who suffer from mental health and well-being problems, but do not know how to get support.

She said: "Young people need to recognise that life's not perfect and we are all going to have hardships and hard times."

Asked what she would tell her teenage self today, Cheryl added: "I would have told myself not to worry so much. Whatever it is you are going through, you will come through it."

Latest Childline figures show almost a quarter increase (22%) in counselling sessions provided for girls aged 12 to18 suffering personal issues such as low self-esteem, depression and self-harm over the last three years - a jump from 31,221 to 38,155.

The charity reports that the number of these sessions for girls who express suicidal feelings has risen by almost a third (28%).

Cheryl changed her birth surname, Tweedy, to Cole when she married Ashley Cole in 2006 and then became Cheryl Fernandez-Versini following her marriage to Jean-Bernard Fernandez-Versini in 2014. The pair were last month granted a decree nisi in their divorce proceedings.

Now going by the mononym Cheryl, she said: "As a teenager I was aware of Childline, but like so many others I mistakenly thought it was just for young kids.

"The reality is that it doesn't matter whether you are at primary, secondary school or college, or how big or small your problem is, Childline is there for you."

To launch her campaign she is featuring in an emotive film, which sees her voice replaced by young people talking about deeply personal problems.

One boy explains how he is gay but is too frightened to tell his father, while a teenage girl talks about being sexually abused at home.